A structure, in which a paper ejection roller and a star wheel (spur) are disposed so as to face each other with a paper sheet to be conveyed therebetween and the paper sheet is held between and conveyed by the paper ejection roller and the star wheel, is used for a paper conveying mechanism in office automation equipment such as printers and facsimiles.
The paper ejection roller and the star wheel are positioned more toward the downstream side in the direction in which paper is conveyed than a recording means such as an ink jet head is, and it is necessary to convey the paper sheet while preventing ink, which has been printed onto the paper sheet by the recording means, from being transferred off the paper as much as possible.
In this regard, a ridged paper ejection roller has been proposed that includes a main shaft body and a plurality of rubber rings press-fitted to the main shaft body (see Patent document 1 below).
Specifically, on one side relative to the surface of a paper sheet, a plurality of star wheels are disposed apart from each other in the width direction of the paper sheet. On the other hand, the ridged paper ejection roller is disposed on the other side relative to the surface of the paper sheet, and the rubber rings are press-fitted to the main shaft body so as to face the respective star wheels. According to this configuration, the corresponding rubber rings and star wheels hold therebetween and convey the paper sheet.
This ridged paper ejection roller can substantially limit the region of the paper ejection roller that comes into contact with the paper sheet only to the rubber rings, and is advantageous in being able to, thereby, prevent ink, which has been printed onto the paper sheet, from being transferred to the paper ejection roller as much as possible. However, the rubber rings have to be press-fitted to the predetermined positions of the main shaft body so as to face the star wheels, it is thus difficult to efficiently manufacture the paper ejection roller, and there is the problem of high manufacturing costs.